1. Field of the Invention
This invention relates to a termination system for telecommunication devices, and in particular to a modular interchange termination system for key telephones.
2. Description of the Prior Art
Telephone termination systems, particularly those associated with key telephones in a business office environment, have heretofore required a great deal of time and expense in connection with installation, maintenance, and line and function alterability.
For example, in such termination systems, incoming trunks are extended, usually underground, from a central office to a distribution frame usually located in a basement or other utility area of an office building. The incoming lines are then fed to second terminal blocks located in individual floor riser closets for connection to the associated key telephones by way of switching and signaling equipment also located in each closet which operates in conjunction with the key telephones to selectively provide multi-line connection and the associated functions of holding, ringing, lamp lighting and the like.
Inasmuch as the terminal blocks and switching and signaling equipment are located in the aforementioned floor closets and as each key telephone requires a multiplicity of conductors for each line connectible thereto and its associated functions for holding, ringing, lamp lighting and the like, and as the key telephones are located at various positions throughout the building, it is readily apparent that a great deal of time and expense is involved in installing "raw" cable, which by way of example usually comprises 25 pair solid conductor color coded insulated cable, between the second terminal blocks and the key telephones throughout a building.
The use of permanent or semi-permanent connections, including lugs and installation-piercing terminals, such as provided by the Western Electric 66A or 66B terminal blocks, gives rise to an additional problem concerning the flexibility of prior systems. For example, if four incoming lines are available and a key telephone has access to two of the four lines, and access is to be altered to three available lines, additional connections must be individually and physically performed at the terminal blocks. This problem is compounded if one of the original two lines is not to service the key telephone. This means that the function conductors associated with the line must be disconnected. With personnel changes in a customer's facility, and with changes of customers, maintenance of the connection system may become a problem. Also, when a customer acquires additional floor space, or shifts personnel to different areas of a given floor space, the function conductors associated with each key telephone must be disconnected and/or connected to different terminals of the terminal blocks. This, of course, requires additional installation and maintenance time for the termination system, not to mention interference with the subscriber's business activities.